Film attaching system

ABSTRACT

Electro-dynamic loudspeakers typically include a diaphragm having a conductor applied to one of its surfaces where the diaphragm is secured to a frame. The conductor is connected to a power supply for providing electrical current through linear traces of the conductor that interact with magnetic fields generated by magnets that are mounted to the frame. The diaphragm is driven by a motive force created when current passes through the conductor within the magnetic field. The electrical current is varied to create an acoustical output from the electro-dynamic loudspeaker. Different methods of attaching the diaphragm are provided for simplifying the manufacturing process and for obtaining a robust electro-dynamic loudspeaker.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/380,001, filed on May 2, 2002; U.S. ProvisionalApplication No. 60/378,188, filed on May 6, 2002; and U.S. ProvisionalApplication No. 60/391,134, filed on Jun. 24, 2002. The disclosures ofthese applications are incorporated herein by reference.

[0002] This application incorporates by reference the disclosures ofeach of the following co-pending applications which have been filedconcurrently with this application: U.S. patent application Ser. No.______, entitled “Mounting Bracket System,” filed May 2, 2003; U.S.patent application Ser. No. ______, entitled “Film Tensioning System,”filed May 2, 2003; U.S. patent application Ser. No. ______, entitled“Electrical Connectors For Electro-Dynamic Loudspeakers,” filed May 2,2003; U.S. patent application Ser. No. ______, entitled “Electro-DynamicLoudspeaker Mounting System,” filed May 2, 2003; U.S. patent applicationSer. No. ______, entitled “Conductors For Electro-Dynamic Loudspeakers,”filed May 2, 2003; U.S. patent application Ser. No. ______, entitled“Frame Structure,” filed May 2, 2003; U.S. patent application Ser. No.______, entitled “Acoustically Enhanced Electro-Dynamic Loudspeakers,”filed May 2, 2003; U.S. patent application Ser. No. ______, entitled“Directivity Control Of Electro-Dynamic Loudspeakers,” filed May 2,2003; U.S. patent application Ser. No. ______, entitled “FrequencyResponse Enhancements For Electro-Dynamic Loudspeakers,” filed May 2,2003; and U.S. patent application Ser. No. ______, entitled “MagnetArrangement For Loudspeaker,” filed May 2, 2003.

BACKGROUND OF THE INVENTION

[0003] 1. Field of Invention.

[0004] The invention relates to electro-dynamic loudspeakers, and moreparticularly, to improvements for electro-dynamic loudspeakers andrelated manufacturing methods.

[0005] 2. Related Art.

[0006] The general construction of an electro-dynamic loudspeakerincludes a diaphragm, in the form of a thin film, attached in tension toa frame. An electrical circuit, in the form of electrically conductivetraces, is applied to the surface of the diaphragm. Magnetic sources,typically in the form of permanent magnets, are mounted adjacent to thediaphragm or within the frame, creating a magnetic field. When currentis flowing in the electrical circuit, the diaphragm vibrates in responseto the interaction between the current and the magnetic field. Thevibration of the diaphragm produces the sound generated by theelectro-dynamic loudspeaker.

[0007] Many design and manufacturing challenges present themselves inthe manufacturing of electro-dynamic loudspeakers. First, the diaphragm,that is formed by a thin film, needs to be permanently attached, intension, to the frame. Correct tension is required to optimize theresonance frequency of the diaphragm. Optimizing diaphragm resonanceextends the bandwidth and reduces sound distortion of the loudspeaker.

[0008] The diaphragm is driven by the motive force created when currentpasses through the conductor applied to the diaphragm within themagnetic field. The conductor on the electro-dynamic loudspeaker isattached directly to the diaphragm. Because the conductor is placeddirectly onto the thin diaphragm, the conductor should be constructed ofa material having a low mass and should also be securely attached to thefilm at high power (large current) and high temperatures.

[0009] Accordingly, designing conductors for electro-dynamic loudspeakerapplications presents various challenges such as selecting the speakerwith the desired audible output for a given location that will fitwithin the size and location constraints of the desired applicationsenvironment. Electro-dynamic loudspeakers exhibit a defined acousticaldirectivity pattern relative to each speaker's physical shape and thefrequency of the audible output produced by each loudspeaker.Consequently, when an audio system is designed, loudspeakers possessinga desired directivity pattern over a given frequency range are selectedto achieve the intended performance of the system. Different loudspeakerdirectivity patterns may be desirable for various loudspeakerapplications. For example, for use in a consumer audio system for a homelistening environment, a wide directivity may be preferred. In theapplication of a loudspeaker, a narrow directivity may be desirable todirect sound, e.g., voice, in a predetermined direction.

[0010] Often, space limitations in the listening environment prohibitthe use of a loudspeaker in an audio system that possesses the preferreddirectivity pattern for the system's design. For example, the amount ofspace and the particular locations available in a listening environmentfor locating and/or mounting the loudspeakers of the audio system mayprohibit the use of a particular loudspeaker that exhibits the intendeddirectivity pattern. Also, due to space and location constraints, it maynot be possible to position or oriented the desired loudspeaker in amanner consistent with the loudspeaker's directivity pattern.Consequently, size and space constraints of a particular environment maymake it difficult to achieve the desired performance from the audiosystem. An example of a listening environment having such constraints isthe interior passenger compartment of an automobile or other vehicle.

[0011] While the electric circuitry of electro-dynamic loudspeakers maypresent design challenges, electro-dynamic loudspeakers are verydesirable loudspeakers because they are designed to have a very shallowdepth. With this dimensional flexibility, electro-dynamic loudspeakersmay be positioned at locations where conventional loudspeakers would nottraditionally fit. This dimensional flexibility is particularlyadvantageous in automotive applications where positioning a loudspeakerat a location that a conventional loudspeaker would not otherwise fitcould offer various advantages. Further, because the final loudspeakerassembly may be mounted on a vehicle, it is important that the assemblybe rigid during shipping and handling so that the diaphragm or framedoes not deform during installation.

[0012] While conventional electro-dynamic loudspeakers are shallow indepth and may therefore be preferred over conventional loudspeakers foruse in environments requiring thin loudspeakers, electro-dynamicloudspeakers have a generally rectangular planar radiator that isgenerally relatively large in height and width to achieve acceptableoperating wavelength sensitivity, power handling, maximum sound pressurelevel capability and low-frequency bandwidth. Unfortunately, the largerectangular size results in a high-frequency beam width angle orcoverage that may be too narrow for its intended application. Thehigh-frequency horizontal and vertical coverage of a rectangular planarradiator is directly related to its width and height in an inverserelationship. As such, large radiator dimensions exhibit narrowhigh-frequency coverage and vice versa.

SUMMARY

[0013] The invention provides several film attaching methods andfixtures related to electro-dynamic loudspeakers. A diaphragm isattached to a frame of an electro-dynamic loudspeaker using adhesivecurable by exposure to radiation. The frame is subsequently deformed toelongate and tension the diaphragm.

[0014] A film clamp is used to temporarily fix a diaphragm in anon-tensioned state. The diaphragm is placed in the non-tensioned stateby placing the diaphragm on a vacuum source having a flat contactsurface. The clamp is structured to contact the diaphragm along aperimeter portion and allow access to a center portion of the diaphragm.The clamped diaphragm is then displaced over a loudspeaker frame toproduce tension in the diaphragm. Once the proper tension has beenproduced, an adhesive curable by exposure to radiation is applied to oneof the diaphragm and the frame. The frame is positioned to sandwich theadhesive between the diaphragm and the frame while the adhesive isirradiated to couple the diaphragm to the frame.

[0015] An apparatus for tensioning a diaphragm includes a spider havinga plurality of fingers radially extending from a hub where each of thefingers includes a pad adapted to contact one side of the diaphragmwhile a base plate contacts an opposite side of the diaphragm. An axialforce is placed upon the spider. The axial force is at least partiallyconverted to a lateral force in the diaphragm to produce a tension inthe diaphragm between the pads. An adhesive curable by exposure toradiation is applied to at least one of the diaphragm and the frame. Theframe is brought into contact with the tensioned diaphragm and theadhesive is irradiated to couple the diaphragm to the frame while thepredetermined tension is maintained.

[0016] A diaphragm is tensioned by placing the diaphragm between a firstplate and a second plate where each of the plates includes an apertureextending through its thickness and an annular groove circumscribing theaperture. The first and second plates are drawn toward one another totension the film. The electro-dynamic loudspeaker frame is coupled tothe diaphragm while tension is maintained in the diaphragm byirradiating an adhesive curable by exposure to radiation positionedbetween the frame and the diaphragm.

[0017] A diaphragm is tensioned by elastically deforming a frame of theelectro-dynamic loudspeaker and coupling a diaphragm to the frame whilethe load is maintained on the frame. The diaphragm is coupled to theframe using an adhesive curable by exposure to radiation. The load onthe frame is released to tension the diaphragm.

[0018] A diaphragm is attached to a frame having a plurality ofprojections extending from a mounting plane. The diaphragm is engagedwith the plurality of projections and energy is input to cause theprojections to melt and couple the diaphragm to the frame.

[0019] A diaphragm is coupled to a frame coated with a thermoplasticmaterial. The interface between the diaphragm and the thermoplasticmaterial is energized to cause localized melting. After removing theenergy source, the diaphragm is bonded to the frame.

[0020] A diaphragm is coupled to a grille to create a grille assembly. Aplurality of magnets are coupled to a frame to create a frame assembly.The grille assembly and the frame assembly are subsequently coupled toconstruct an electro-dynamic loudspeaker.

[0021] A diaphragm is coupled to a frame including a plurality of pinsextending from a mounting plane. The pins extend through a plurality ofapertures extending through the diaphragm. A distal end of each pin isdeformed to define a head portion to retain the diaphragm to the frame.

[0022] A diaphragm having an electrical conductor coupled thereto iscoupled to a frame having a plurality of projections extending from asurface. The diaphragm is coupled to the frame using an ultrasonicwelder.

[0023] Other systems, methods, features and advantages of the inventionwill be or will become apparent to one with skill in the art uponexamination of the following figures and detailed description. It isintended that all such additional systems, methods, features andadvantages be included within this description, be within the scope ofthe invention, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention can be better understood with reference to thefollowing drawings and description. The components in the figures arenot necessarily to scale, emphasis instead being placed uponillustrating the principles of the invention. Moreover, in the figures,like reference numerals designate corresponding parts throughout thedifferent views.

[0025]FIG. 1 is a perspective view of an electro-dynamic loudspeaker asit would appear with the grille removed.

[0026]FIG. 2 is an exploded perspective view of the electro-dynamicloudspeaker shown in FIG. 1 having a grille.

[0027]FIG. 3 is a cross-sectional view of the electro-dynamicloudspeaker taken along line 3-3 of FIG. 1.

[0028]FIG. 4 is an enlarged cross-sectional view of the encircled areaof FIG. 3.

[0029]FIG. 5 is a plan view showing a conductor on a diaphragm of anelectro-dynamic loudspeaker.

[0030]FIG. 6 is a plan view of a vacuum platen for use in constructingan electro-dynamic loudspeaker.

[0031]FIG. 7 is a cross-sectional side view of the vacuum platen shownin FIG. 6.

[0032]FIG. 8 is a perspective view of a clamp assembly for use inconstructing an electro-dynamic loudspeaker.

[0033]FIG. 9 is a cross-sectional side view of the clamp assembly ofFIG. 8.

[0034]FIG. 10 is a plan view of the clamp assembly in a closed position.

[0035]FIG. 1I is a cross-sectional side view of the clamp assembly inthe closed position.

[0036]FIG. 12 is a plan view of an assembly fixture for assembling anelectro-dynamic loudspeaker.

[0037]FIG. 13 is a cross-sectional side view of the assembly fixture.

[0038]FIG. 14 is a plan view of the clamp assembly positioned atop theassembly fixture.

[0039]FIG. 15 is a cross-sectional side view of the closed clampassembly positioned atop the assembly fixture.

[0040]FIG. 16 is cross-sectional side view of a work-in-processelectro-dynamic loudspeaker.

[0041]FIG. 17 is a cross-sectional side view of a finishedelectro-dynamic loudspeaker.

[0042]FIG. 18 is a cross-sectional view of a film tensioning device.

[0043]FIG. 19 is a cross-sectional side view of an alternate filmtensioning device.

[0044]FIG. 20 is a perspective view of a generally frusto-conicallyshaped tensioning member.

[0045]FIG. 21 is a cross-sectional side view depicting an alternatetensioning method using the frusto-conical member shown in FIG. 20.

[0046]FIG. 22 is a cross-sectional side view further depicting diaphragmtensioning using the frusto-conical member of FIG. 20.

[0047]FIG. 23 depicts a frame in an undeformed state and a deformedstate.

[0048]FIG. 24 is a plan view of an electro-dynamic loudspeaker assemblysystem.

[0049]FIG. 25 is a perspective view of a pallet for use in the assemblysystem.

[0050]FIG. 26 is a perspective view of an adhesive application station.

[0051]FIG. 27 is a perspective view of a magnet loading and adhesiveactivator application station.

[0052]FIG. 28 is a perspective view of a magnetization station.

[0053]FIG. 29 is a perspective view of an adhesive application station.

[0054]FIG. 30 is a perspective view of a diaphragm loading station.

[0055]FIG. 31 is a cross-sectional view of speaker components andfixturing located after completing diaphragm loading as depicted in FIG.30.

[0056]FIG. 32 is a perspective view of an edge treatment compoundapplication station.

[0057]FIG. 33 is a perspective view of a clamping and irradiationstation.

[0058]FIG. 34 is a perspective view of a terminal crimping station.

[0059]FIG. 35 is a perspective view of a diaphragm trimming station.

[0060]FIG. 36 is a cross-sectional view depicting a grille and diaphragmsubassembly positioned adjacent a frame and magnet subassembly.

[0061]FIG. 37 is an exploded perspective view depicting an alternatediaphragm and frame attachment mechanism.

[0062]FIG. 38 is a cross-sectional view of the diaphragm and frame ofFIG. 37 coupled to one another.

[0063]FIG. 39 is a cross-sectional view of an alternate diaphragm andframe attachment mechanism.

[0064]FIG. 40 is a partial cross-sectional view of another diaphragm andframe attachment mechanism.

[0065]FIG. 41 is a perspective view of the pallet having a lower clampframe and an upper clamp frame positioned thereon.

[0066]FIG. 42 is a perspective view of a felt cutting and loadingstation.

[0067]FIG. 43 is a perspective view of a frame loading station.

DETAILED DESCRIPTION

[0068]FIG. 1 is a perspective view of an electro-dynamic loudspeaker 100of the invention. As shown in FIG. 1, the electro-dynamic loudspeaker isa generally planar loudspeaker having a frame 102 with a diaphragm 104attached in tension to the frame 102. A conductor 106 is positioned onthe diaphragm 104. The conductor 106 is shaped in serpentine fashionhaving a plurality of substantially linear sections (or traces) 108longitudinally extending along the diaphragm interconnected by radii 110to form a single current path. Permanent magnets 202 (shown in FIG. 2)are positioned on the frame 102 underneath the diaphragm 104, creating amagnetic field.

[0069] Linear sections 108 are positioned within the flux fieldsgenerated by permanent magnets 202. The linear sections 108 carrycurrent in a first direction 112 and are positioned within magnetic fluxfields having similar directional polarization. Linear sections 108 ofconductor 106 having current flowing in a second direction 114, that isopposite the first direction 112, are placed within magnetic flux fieldshaving an opposite directional polarization. Positioning the linearsections 108 in this manner assures that a driving force is generated bythe interaction between the magnetic fields developed by magnets 202 andthe magnetic fields developed by current flowing in conductor 106. Assuch, an electrical input signal traveling through the conductor 106causes the diaphragm 104 to move, thereby producing an acousticaloutput.

[0070]FIG. 2 is an exploded perspective view of the electro-dynamicloudspeaker 100 shown in FIG. 1. As illustrated in FIG. 2, the flatpanel loudspeaker 100 includes a frame 102, a plurality of high energymagnets 202, a diaphragm 104, an acoustical dampener 236 and a grille228. Frame 102 provides a structure for fixing magnets 202 in apredetermined relationship to one another. In the depicted embodiment,magnets 202 are positioned to define five rows of magnets 202 with threemagnets 202 in each row. The rows are arranged with alternating polaritysuch that fields of magnetic flux are created between each row. Once theflux fields have been defined, diaphragm 104 is fixed to frame 102 alongits periphery.

[0071] A conductor 106 is coupled to the diaphragm 104. The conductor106 is generally formed as an aluminum foil bonded to the diaphragm 104.The conductor 106 can, however, be formed from other conductivematerials. The conductor 106 has a first end 204 and a second end 206positioned adjacent to one another at one end of the diaphragm 104.

[0072] As shown in FIG. 2, frame 102 is a generally dish-shaped memberpreferably constructed from a substantially planar contiguous steelsheet. The frame 102 includes a base plate 208 surrounded by a wall 210.The wall 210 terminates at a radially extending flange 212. The frame102 further includes apertures 214 and 216 extending through flange 212to provide clearance and mounting provisions for a conductor assembly230.

[0073] Conductor assembly 230 includes a terminal board 218, a firstterminal 220 and a second terminal 222. Terminal board 218 includes amounting aperture 224 and is preferably constructed from an electricallyinsulating material such as plastic, fiberglass or other insulatingmaterial. A pair of rivets or other connectors (not shown) pass throughapertures 214 to electrically couple first terminal 220 to first end 204and second terminal 222 to second end 206 of conductor 106. A fastenersuch as a rivet 226 extends through apertures 224 and 216 to coupleconductor assembly 230 to frame 102.

[0074] A grille 228 functions to protect diaphragm 104 from contact withobjects inside the listening environment while also providing a methodfor mounting loudspeaker 100. The grille 228 has a substantially planarbody 238 having a plurality of apertures 232 extending through thecentral portion of the planar body 238. A rim 234 extends downward,substantially orthogonally from body 238, along its perimeter and isdesigned to engage the frame 102 to couple the grille 228 to the frame102.

[0075] An acoustical dampener 236 is mounted on the underside of thebase plate 208 of the frame 102. Dampener 236 serves to dissipateacoustical energy generated by diaphragm 104 thereby minimizingundesirable amplitude peaks during operation. The dampener 236 may bemade of felt, or a similar gas permeable material.

[0076]FIG. 3 is a cross-sectional view of the electro-dynamicloudspeaker taken along line 3-3 of FIG. 1. FIG. 3 shows the frame 102having the diaphragm 104 attached in tension to the frame 102 and thepermanent magnets 202 positioned on the frame 102 underneath thediaphragm 104. Linear sections 108 of the conductor 106 are also shownpositioned on top of the diaphragm 104.

[0077]FIG. 4 is an enlarged cross-sectional view of the encircled areaof FIG. 3. As illustrated by FIG. 4, the diaphragm 104 is comprised of athin film 400 having a first side 402 and a second side 404. First side402 is coupled to frame 102. Generally, the diaphragm 104 is secured tothe frame 102 by an adhesive 406 that is curable by exposure toradiation. However, the diaphragm 104 may secured to the frame 102 byother mechanism, such as those known in the art.

[0078] To provide a movable membrane capable of producing sound, thediaphragm 104 is mounted to the frame in a state of tension and spacedapart a predetermined distance from magnets 202. The magnitude oftension of the diaphragm 104 depends on the speaker's physicaldimensions, materials used to construct the diaphragm 104 and thestrength of the magnetic field generated by magnets 202. Magnets 202 aregenerally constructed from a highly energizable material such asneodymium iron boron (NdFeB), but may be made of other magneticmaterials. The thin diaphragm film 400 is generally apolyethylenenaphthalate sheet having a thickness of approximately 0.001inches; however, the diaphragm film 400 may be formed from materialssuch as polyester (e.g., known by the tradename “Mylar”), polyamide(e.g., known by the tradename “Kapton”) and polycarbonate (e.g., knownby the tradename “Lexan”), and other materials known by those skilled inthe art for forming diaphragms 104.

[0079] The conductor 106 is coupled to the second side 404 of thediaphragm film 400. The conductor 106 is generally formed as an aluminumfoil bonded to diaphragm film 400, but may be formed of other conductivematerial known by those skilled in the art.

[0080] The frame 102 includes a base plate 208 surrounded by a wall 210extending generally orthogonally upward from the plate 208. The wall 210terminates at a radially extending flange 212 that defines asubstantially planar mounting surface 414. A lip 416 extends downwardlyfrom flange 212 in a direction substantially parallel to wall 210. Baseplate 208 includes a first surface 418, a second surface 420 and aplurality of apertures 422 extending through the base plate 208. Theapertures 422 are positioned and sized to provide air passagewaysbetween the first side 402 of diaphragm 104 and first surface 418 offrame 102. An acoustical dampener 236 is mounted to second surface 420of frame base plate 208.

[0081] Various systems for assembling an example loudspeaker 100 willnow be described. A first example system is depicted in FIGS. 5-17. Thefirst system includes a vacuum platen 600 (FIGS. 6-7) and a film clamp800 (FIGS. 8-9). Vacuum platen 600 and film clamp 800 may be used inconjunction with one another to restrain diaphragm 104 (FIG. 5) in aflat position without tension. Once diaphragm 104 is fixed within clamp800, film 400 may be subsequently tensioned as will be described later.

[0082] The initial flattening and clamping of diaphragm 104 may providethe assembler with a known diaphragm state to which tension may beadded. Difficulties may arise in attempting to obtain a reproducibletension during subsequent assembly operations when diaphragm 104 is notfirst placed in a substantially flat, no tension state. This firstexample system includes vacuum platen 600 and film clamp 800 to achievea repeatable diaphragm state. In other examples, any other mechanism(s)and/or techniques capable of providing a known diaphragm state to whichtension may be added may be used.

[0083] The example vacuum platen 600 includes a base 700 having a body702 and a pedestal 704 protruding from a first surface 602 of body 702.Pedestal 704 includes an upper surface 706 positioned substantiallyparallel to first surface 602. A vacuum passageway 708 may extendthrough pedestal 704 and body 702 to couple upper surface 706 with avacuum source 604. A cap 710 may be coupled to pedestal 704 along uppersurface 706. Cap 710 may be constructed from a gas permeable materialsuch as porous aluminum. Base 700 may be constructed from a gasimpermeable material. Accordingly, a suction force is created along anupper surface 606 of cap 710 when vacuum source 604 draws a vacuum invacuum passageway 708.

[0084] The example film clamp 800 includes an upper clamp half 802 and alower clamp half 804 connected by a hinge 806. The illustrated upperclamp half 802 includes a generally rectangularly shaped body 808 and anelastomeric gasket 810. Body 808 includes an aperture 900 (FIG. 9)extending through body 808. Elastomeric gasket 810 includes a similarlyshaped aperture 902 (FIG. 9) extending through the thickness of gasket810. Elastomeric gasket 810 may be attached to body 808 to provide acompressible high friction surface 812 for engagement with diaphragm104.

[0085] The illustrated lower clamp half 804 is constructed from agenerally rectangularly shaped aluminum frame 814 having an aperture 904extending through the lower clamp half 804. Lower clamp half 804includes an upper surface 906 and a lower surface 908.

[0086] During the loudspeaker assembly process, film clamp 800 may bepositioned on vacuum platen 600 such that pedestal 704 enters aperture904 of lower clamp half 804 as illustrated in FIG. 9. Once seated, uppersurface 906 of lower clamp half 804 may be substantially coplanar withupper surface 606 of cap 710. In order to properly position diaphragm104, upper clamp half 802 may be rotated to place film clamp 800 in theopen position depicted in FIG. 8.

[0087] With vacuum source 604 turned off, diaphragm 104 may be placed onupper surface 606. Diaphragm 104 may be aligned relative to lower clamphalf 804 using sights 816. Sights 816 may be visual markings, rods,rings, notches or any other form of alignment mechanism formed ondiaphragm 104 to assist in the alignment procedure. The location ofsights 816 effectively defines a perimeter portion 818 and a centerportion 820 of diaphragm 104. Center portion 820 may contain most, ifnot all, of the material which will remain coupled to frame 102 at thecompletion of the assembly process.

[0088] Once diaphragm 104 has been properly positioned, vacuum may besupplied to cap 710 via vacuum source 604. Because cap 710 isconstructed from a gas permeable material, diaphragm 104 is forced toclosely conform to planar upper surface 606. While the vacuum source ismaintained, upper clamp half 802 may be rotated to place film clamp 800in a closed position as shown in FIGS. 10 and 11. During clamp closure,elastomeric gasket 810 may deform locally to account for the thicknessof diaphragm 104. Latches 822 secure upper clamp half 802 to lower clamphalf 804. It should be appreciated that latches 822 are merely exemplarydevices for coupling the clamp halves together and that any number offastening devices may be implemented. Once upper clamp half 802 isclamped to lower clamp half 804, vacuum is turned off and film clamp 800holding diaphragm 104 in an untensioned state is removed from vacuumplaten 600.

[0089] Frame 102 may be fixtured in an example assembly fixture 1200(FIGS. 12 and 13). Assembly fixture 1200 may be shaped substantiallysimilarly to vacuum platen 600. However, assembly fixture 1200 mayinclude a recess 1300 for receipt of a portion of frame 102. Assemblyfixture 1200 includes a gage surface 1302 offset a predetermineddistance 1304 from planar mounting surface 408 of frame 102. In order toapply tension to diaphragm 104, distance 1304 is greater than thethickness of lower clamp half 804. The magnitude of tension generated isoptimized by defining distance 1304 in concert with the physicalcharacteristics of frame 102 and diaphragm 104.

[0090] Diaphragm 104 may be mechanically coupled with frame 102. Forexample, adhesive 406 may be applied to planar mounting surface 408 offrame 102. Adhesive 406 may alternatively be applied to diaphragm 104.After application of adhesive 406, film clamp 800 including clampeddiaphragm 104 may be positioned on assembly fixture 1200 such that frame102 enters aperture 904 of lower clamp half 804 (FIGS. 14 and 15). Thediaphragm 104 may contact adhesive 406 and planar mounting surface 408of frame 102. Contact may occur prior to lower surface 908 of lowerclamp half 804 contacting gage surface 1302 of assembly fixture 1200. Toproduce the desired tension in film 400, film clamp 800 is forced downover assembly fixture 1200 so that lower surface 908 engages gagesurface 1302.

[0091] Depending on the type of adhesive used, a subsequent process maybe required. For example, adhesive 406 is curable by exposure toradiation. Accordingly, while film clamp 800 is coupled to assemblyfixture 1200, a radiation source 1500 is energized to cure the adhesiveand secure diaphragm 104 to frame 102. Alternatively, where some othermechanical coupling mechanism is used, appropriate processes may need tobe performed.

[0092] A second example system used to tension the diaphragm of aloudspeaker 100 is described with reference to FIGS. 16 and 17. In thissystem, frame 102 includes an elongated radially extending flange 1600which does not include a downwardly extending lip. The remaining planarloudspeaker components are substantially similar to those previouslydescribed. The assembly process may include positioning diaphragm 104 ina substantially flat, no tension state as previously described. However,it should be appreciated that the flattening and clamping steps are notnecessarily required to construct planar loudspeaker according to thissystem. Similarly, alternate tensioning methods that are described arenot intended to be limited to include the flattening and clampingprocess.

[0093] A bead of adhesive 406 may be applied along the periphery ofeither or both frame 102 and diaphragm 104. Diaphragm 104 may then bealigned with and bonded to frame 102 via adhesive 406. As noted earlier,adhesive 406 may be a light curable material or any other suitablebonding agent which may affix the dissimilar materials to one another.Similarly, adhesive 406 may any other coupling mechanism to mechanicallycouple the diaphragm 104 to the frame 102.

[0094] Radially extending flange 1600 may be mechanically deformed bybending an outer peripheral region down from line 1700 as shown in FIG.17 to tension diaphragm 104. Line 1700 acts as a fulcrum around theperimeter of frame 102 about which diaphragm 104 is stretched. Theproper diaphragm tension may be obtained in a variety of ways. Forexample, if diaphragm 104 was initially coupled to frame 102 in asubstantially flat, non-tension state, a deflection distance 1702 may beempirically determined by testing. Once the proper deflection distanceis determined, hard tooling may be created to repeatably deform frame102 and move radially extending flange 1600 the predetermined deflectiondistance 1702 during the assembly of each loudspeaker 100.

[0095] Another example system of assuring proper film tension includes afeedback system 1602. One example feedback system may involve placing aknown load at the center of diaphragm 104 and measuring the deflectionof the diaphragm at the load application point. The desired deflectionper load may be empirically determined by testing where the resonancefrequency of diaphragm 104 is plotted against deflection per a givenload. Once the desired resonance frequency is determined for a givenspeaker geometry, a target diaphragm deflection per given load may bedetermined. The feedback system may operate by measuring the actualdiaphragm deflection at a known load with a deflection sensor 1604. Themeasured actual deflection may be compared to the target deflection.

[0096] Frame 102 may be deformed until the measured deflection issubstantially equal to the target deflection, thereby properlytensioning diaphragm 104 to produce the desired resonance frequency.Logic control systems such as proportional, integral, derivative closedfeedback loops, etc. may be implemented to control the mechanicaldeflection of frame 102 during the tensioning process. Such a controlsystem may provide a high degree of repeatability regarding filmtensioning.

[0097] Another example feedback system 1704 may directly measureresonance frequency during film tensioning using a frequency sensor1706. In this control scheme, diaphragm 104 may be repeatedly excitedand the resonance frequency measured. The measured frequency may becompared to a desired target frequency during film tensioning. Frame 102may be deformed until the measured resonance frequency matches thetarget frequency within an acceptable tolerance. It should beappreciated that the feedback systems described may be used with any ofthe tensioning techniques described.

[0098] Yet another film tensioning system will be described in greaterdetail with reference to FIG. 18. An example film tensioner 1800includes an upper plate 1802 and a lower plate 1804. Plates 1802 and1804 have matching beveled apertures 1806 and 1808, respectively. Centerportion 820 of diaphragm 104 is positioned within the openings definedby apertures 1806 and 1808. Apertures 1806 and 1808 may be sized andshaped slightly larger than frame 102 to allow insertion of frame 102within one of the apertures 1806 and 1808.

[0099] Upper plate 1802 may include an annular groove 1810 having anasymmetrical cross-section as shown in FIG. 18. Lower plate 1804 mayinclude an annular groove 1812 shaped as the mirror image of groove1810. A first elastomeric member 1814 may be positioned within groove1810 and a second elastomeric member 1816 may be positioned withingroove 1812. Grooves 1810 and 1812 may be shaped to constrain movementof the elastomeric members 1814 and 1816 toward apertures 1806 and 1808,respectively. In addition, grooves 1810 and 1812 may be shaped to allowmovement of elastomeric members 1814 and 1816 away from apertures 1806and 1808. Specifically, the annular grooves 1810 and 1812 may be shapedto impart a lateral force to center portion 820 of diaphragm 104 when anaxial force is applied to upper plate 1802 and lower plate 1804 drawingthem toward one another.

[0100] Upper plate 1802 may also include threaded apertures 1818.Stepped apertures 1820 extend through lower plate 1804. Threadedfasteners 1822, which are illustrated as bolts, may be inserted inapertures 1820 and tightened into threaded apertures 1818 to draw upperplate 1802 and lower plate 1804 together. It should be appreciated thatupper plate 1802 and lower plate 1804 may be drawn together using avariety of mechanisms such as toggle clamps, jack screws, hydrauliccylinders or any other known clamping and force producing devices.

[0101] In this example technique, the film may first be tensioned bydrawing upper plate 1802 and lower plate 1804 together. Adhesive 406 (orsome other coupling mechanism) may be placed on the tensioned portion ofdiaphragm 104 and/or planar mounting surface 408 of frame 102. Whileupper plate 1802 is clamped to lower plate 1804, frame 102 may be placedinto contact with diaphragm 104. Once the adhesive has cured (ormechanical coupling completed), the threaded fasteners 1822 may beremoved and upper plate 1802 may be separated from lower plate 1804. Itshould also be appreciated that apertures 1806 and 1808 may be sized toallow entry of light waves to cure adhesive 406, or to allowmanipulation of some other coupling mechanism, if so desired. Dependingon the specific configuration of the loudspeaker 100, perimeter portion818 of diaphragm 104 may be trimmed to remove any film extending beyondlip 306.

[0102] With reference to FIG. 19, another example film tensioningtechnique is depicted. The fixturing used to practice this exampletechnique includes a fixture 1900 having a lower die 1902, and an upperdie 1904. Fixture 1900 may function to restrain the periphery ofdiaphragm 104 and define a cavity 1906 between one side of the diaphragm104 and lower die 1902. A fluid source 1908 may supply pressurized fluidto cavity 1906. Because lower die 1902 is constructed from asubstantially rigid material, diaphragm 104 may elongate in tension asdepicted in FIG. 19. Pressure is maintained within cavity 1906 whileframe 102 is mechanically coupled with diaphragm 104. Diaphragm 104 maybe secured to frame 102 using any number of previously discussed bondingtechniques including mechanical fasteners, radiation curable adhesives,multi-part epoxies, heat curable adhesives or pressure sensitivecompounds.

[0103] After diaphragm 104 has been fixed to frame 102, upper die 1904may be removed. If desired, excess diaphragm material extending beyondthe perimeter of frame 102 may be removed.

[0104] In this example technique, some of the initial tension generatedby the pressurized fluid may relax during subsequent frame attachmentprocess. Accordingly, a tension greater than the final desired tensionmay be initially induced via fluid source 1908 to assure that the filmis properly tensioned during use.

[0105] FIGS. 20-22 depict another example of fixturing used to tensiondiaphragm 104 prior to attaching diaphragm 104 to frame 102. An examplespider 2000 may operate in conjunction with an example base plate 2100to tension diaphragm 104. Spider 2000 may be placed on a first side ofdiaphragm 104 while base plate 2100 may be placed on the opposite sideof the diaphragm 104. Spider 2000 may function by converting an axialforce applied in direction 2102 to a lateral tension produced in opposeddirections 2200.

[0106] The illustrated spider 2000 is a generally pyramidal memberhaving a hub 2002 positioned proximate to a truncated portion of thepyramid. A plurality of legs 2004 angularly extend from hub 2002. Eachof the legs 2004 include a body portion 2006 and a foot portion 2008.Each foot portion 2008 radially extends from the distal end of each leg2004. A pad 2010 is coupled (as shown in FIG. 20) to a lower surface ofeach foot 2008. Pads 2010 may be constructed from a high friction,elastomeric material that is suitable for gripping diaphragm 104 withoutcausing damage to diaphragm 104.

[0107] The illustrated base plate 2100 is a generallyrectangularly-shaped member having an aperture 2104 extending throughthe base plate 2100. Aperture 2104 may be shaped similarly to theperimeter of frame 102 and sized such that frame 102 may be insertedinto aperture 2104. Base plate 2100 includes a low friction surface 2106upon which diaphragm 104 may freely slide. As best shown in FIG. 21,each pad 2010 is supported by a portion of base plate 2100.

[0108] During tensioning, diaphragm 104 may be placed between base plate2100 and spider 2000. An axial force may be applied to spider 2000 indirection 2102. Due to the angular orientation of legs 2004 relative tolow friction surface 2106, at least some of the axial force applied indirection 2102 may be converted to opposing forces in opposed directions2200. The opposed forces may tension diaphragm 104. After tensioning,frame 102 is mechanically coupled to diaphragm 104 as previouslydiscussed.

[0109]FIG. 23, is yet another example system for loudspeaker 100assembly. In this system, frame 102 may be elastically deformed prior toattachment of diaphragm 104. The deformed frame 102 is represented inphantom lines at reference numeral 2300. It should be appreciated thatany number of force generating devices or tools such as jack screws,hydraulic rams or other force producing devices may be used toelastically deform frame 102 by inwardly deflecting radially extendingflange 304 and lip 306 (FIG. 3) of frame 102. Frame 102 may bemaintained in the deformed state shown as 2300 while diaphragm 104(FIG. 1) is attached to planar mounting surface 408 (FIG. 4).

[0110] Once diaphragm 104 has been securely attached to frame 102, theexternal forces deforming frame 102 may be released. Because frame 102was elastically deformed, flange 304 and lip 306 have a tendency tospring-back to their originally undeformed state. This tendency isresisted by diaphragm 104. Diaphragm 104 elongates as the deformed frameattempts to return to its undeformed state until an equilibrium isreached. Frame 102 may be constructed from steel, aluminum or any numberof composite materials capable of being deformed. Materials having amodulus of elasticity less than 29,000 KSI are contemplated to provide arelatively large elastic deformation prior to yield. A large framedeformation is beneficial to account for elongation or deformation ofadhesive 406 or other mechanical coupling used to bond diaphragm 104 toframe 102.

[0111] An example planar loudspeaker assembly system 2400 is depicted inFIG. 24. Planar loudspeaker assembly system 2400 functions to constructa fully tested and finished planar loudspeaker from a variety ofseparate components in a relatively small space and a minimal amount oftime.

[0112] Assembly system 2400 is a conveyor-type system utilizing aplurality of pallets 2402 traveling about a closed loop. Each of pallets2402 is engaged by a drive belt or track 2404 to move the pallets 2402around the loop in a counter-clockwise direction. A plurality ofworkstations 2406 are positioned along track 2404 to perform the processsteps.

[0113] As best shown in FIG. 25, pallet 2402 includes a first protrusion2500 and a second protrusion 2502 extending upwardly from an uppersurface 2504. First protrusion 2500 includes a recess 2505. Secondprotrusion 2502 is rectangularly shaped and surrounds an aperture 2506.Aperture 2506 extends through the thickness of pallet 2402. Secondprotrusion 2502 includes a stepped sidewall 2508. Stepped sidewall 2508includes a lower portion 2510. Stepped sidewall 2508 includes an upperportion 2512 that serves as a locating structure for frame 102. As shownin FIG. 41, an upper clamp half 4100 is placed over first protrusion2500. A lower clamp half 4102 is positioned over second protrusion 2502.

[0114] With reference to FIG. 42, pallet 2402 travels to a felt cuttingand loading station 4200. The felt cutting and loading station 4200includes a frame 4201, a dispenser 4202, a cutter 4204 and a robot 4206having an end effecter 4208 coupled to robot 4206. A roll of felt 4210is rotatably coupled to frame 4201. The free end of the roll of felt4210 is fed into dispenser 4202. Dispenser 4202 is controllable toselectively index a portion of the roll of felt onto a block 4212. Oncethe appropriate width of felt has been dispensed on block 4212, feeder4202 halts movement of felt roll 4210. Cutter 4204 separates a singularfelt panel 4214 from the roll. At this time, robot 4206 positionsend-effector 4208 above felt panel 4214 located on block 4212. Throughthe use of vacuum or a cloth gripping device, end-effector 4208transfers felt panel 4214 to recess 2505 located in first protrusion2500.

[0115] Pallet 2402 travels to a frame loading station 4300 shown in FIG.43. Frame loading station 4300 includes a dial table 4301, a hot meltapplicator 4302 and a robot 4304. Dial table 4301 includes three stacks4306 rotatably mounted to a base 4308. The stack positioned beneathrobot 4304 is defined as being in the active position. The other twostacks 4306 are positioned at inactive positions. An operator positionedadjacent inactive stacks 4306 loads frames 102 for later use at theactive position. An elevator (not shown) positioned below dial table4301 maintains the position of the upper most frame within the activestack at a predetermined elevation.

[0116] During operation of frame loading station 4300, robot 4304positions a magnetic or vacuum end-effector 4310 over the active stackposition. The end-effector removes the top frame from the active stackand rolls it across hot melt applicator 4302. Robot 4304 continues totranslate frame 102 to a position over felt panel 4214. Frame 102,including a coating of hot melt adhesive, is pressed into contact withfelt panel 4214 to adhere the felt to the frame. End-effector 4310 thenplaces the frame and felt subassembly on upper portion 2512 of secondprotrusion 2502. Operation of frame loading station 4300 continues inthis manner until all of the frames within the active stack have beenused. At this time, dial table 4301 indexes to place one of thepreviously inactive stacks at the active stack location. An operatorthen fills the empty stack 4306 with frames 102.

[0117] As shown in FIG. 26, pallet 2402 continues to travel in acounter-clockwise direction through an adhesive application station2600. Station 2600 includes five adhesive valves 2602 positioned in anoffset manner to one another. Pallet 2402 passes under adhesive valves2602 at a uniform rate. Each adhesive valve 2602 lowers to a dispensingheight and applies an adhesive 2604 at an appropriate time to dispensefive equally spaced ribbons of adhesive 2604 on frame 102. The openingand closing of valves 2602 is timed to correspond to the movement ofpallet 2402. Five equal length adhesive ribbons 2604 are dispensed onframe 102 without stopping pallet 2402.

[0118] Pallet 2402 continues to travel to a magnet loading station 2700depicted at FIG. 27. At magnet loading station 2700, a bowl feeder 2702presents fifteen magnets 202 correctly oriented in a pattern of fiverows and three columns. It should be appreciated that other high speedfeeding mechanisms may be utilized to correctly present and orientmagnets 202. Referring to FIG. 27, an end-effector 2704 is mounted to arobot or pick-and-place mechanism 2706 to allow movement of end-effector2704 within station 2700. End-effector 2704 is positioned immediatelyabove placed magnets 202 at bowl feeder 2702. End-effector 2704 is thenenergized to temporarily couple magnets 202 to end-effector 2704. Robot2706 then moves end-effector 2704 above an adhesive activator applicatorpad 2708. Each of magnets 202 attached to end-effector 2704 are thenpressed against adhesive activator applicator pad 2708 to apply anadhesive activator 2710 to the bottom of magnets 202. End-effector 2704along with magnets 202 are next indexed to a location above frame 102.End-effector 2704 is axially lowered to press magnets 202 into adhesive2604 and mix adhesive activator 2710 with adhesive 2604 to start thechemical reaction to secure magnets 202 to frame 102. Adhesive 2604 andadhesive activator 2710 illustratively complete a two-part adhesive. Oneskilled in the art will appreciate that the two-part adhesive is merelyexemplary and that a variety of other magnet bonding methods may beincorporated without departing from the scope of the invention. Forexample, a one-part heat curable adhesive, mechanical fasteners, orwelding techniques may be used.

[0119] Pallet 2402 next travels along track 2404 to acrylic curingstations 2410. Pallet 2402 passes through acrylic curing stations 2410to allow the two-part adhesive time to cure. After magnets 202 arefirmly secured to frame 102, they are magnetized at a magnetizingstation 2800. Within magnetization station 2800, frame 102 is raised tobe within close proximity to an energy source 2802. Each of the magnetswithin any one row are magnetized having the same polarity. Magnets ofimmediately adjacent rows are magnetized with the opposite polarity tocreate the magnetic flux fields described earlier. After energization,frame 102 and magnets 202 are separated from energy source 2802 via acylinder 2805 and lowered onto pallet 2402. Specifically, a plate 2806including a plurality of posts 2808 are lowered such that two posts 2808contact each magnet to separate the magnetized magnets and frame fromenergy source 2802.

[0120] After magnetization, pallet 2402 travels to diaphragm adhesiveapplication station 2900 shown in FIG. 29. Station 2900 includes anadhesive applicator 2902 mounted to a Cartesian arm 2904. Adhesiveapplicator 2902 applies adhesive 406 to planar mounting surface 414 offrame 102. In the preferred embodiment, movement of pallet 2402 iscontrolled while adhesive is being applied. Motion control along an Xaxis will be provided by track 2404 and motion along the Y and Z axeswill be provided by Cartesian arm 2904.

[0121] Pallet 2402 next travels to a diaphragm loading station 3000.Diaphragm loading station 3000 loads diaphragm 104 onto frame 102. In apreferred embodiment, a roll 3002 of diaphragms 104 is rotatably mountedon a frame 3004. The roll 3002 of diaphragms 104 consists of acontinuous sheet of film 400 having a plurality of conductors 106 spacedapart and positioned along the length of film 400. The continuous sheetof film 400 is rolled for convenient handling in a productionenvironment. A free end of diaphragm roll 3002 is inserted into a feeder3006. Feeder 3006 is positioned adjacent a vacuum platen 3008. Duringoperation, feeder 3006 is selectively operable to dispense material fromdiaphragm roll 3002 onto an upper surface 3010 of vacuum platen 3008. Avision system 3012 includes a controller 3014 and a camera 3016. Camera3016 is preferably positioned atop frame 3004 to have a clear view ofthe end portion of diaphragm roll 3002 being positioned on upper surface3010 of vacuum platen 3008. Camera 3016 communicates diaphragm positioninformation to controller 3014.

[0122] Once the free end of diaphragm roll 3002 has been indexed to adesired position to position a diaphragm 104 on upper surface 3010 ofvacuum platen 3008, controller 3014 instructs feeder 3006 to maintainthe current position of the diaphragm roll. Camera 3016 alsocommunicates the lateral position of the conductor 106 on the diaphragm104 on upper surface 3010 of vacuum platen 3008 to controller 3014. Theposition of pallet 2402 is adjusted to align speaker frame 102 with thecurrent position of the conductor 106 on the upper surface 3010 ofvacuum platen 3008.

[0123] Once the pallet and diaphragm 104 on upper surface 3010 of vacuumplaten 3008 have been positioned as described, vacuum is applied tovacuum platen 3008. As such, the end portion of diaphragm roll 3002containing diaphragm 104 that is positioned on upper surface 3010 ofvacuum platen 3008 is temporarily fixed to vacuum platen 3008. A cutter3018 separates diaphragm 104 from diaphragm roll 3002.

[0124] After diaphragm 104 is severed from diaphragm roll 3002, anend-effector 3020 picks up upper clamp half 3600 from its storageposition on pallet 2402. End-effector 3020 positions upper clamp half3600 on the cut diaphragm while vacuum is supplied to vacuum platen3008. End-effector 3020 next supplies vacuum to the perimeter of upperclamp half 3600 as well. The vacuum supply to vacuum platen 3008 isturned off and a slight positive pressure is applied to diaphragm 104from upper surface 3010 of vacuum platen 3008. Next, end-effector 3020transfers upper clamp half 3600 and diaphragm 104 to a position overpallet 2402. End-effector 3020 then lowers upper clamp half 3600 anddiaphragm 104 into contact with lower clamp half 3602 effectivelytrapping diaphragm 104 between the upper and lower clamp halves in anon-tension state. The vacuum supplied to end-effector 3020 is turnedoff and end-effector 3020 releases upper clamp half 3600 to complete thecycle at diaphragm loading station 3000.

[0125] With reference to FIG. 31, pallet 2402 is depicted incross-section after the process steps conducted at diaphragm loadingstation 3000 have been completed. At this time, lower clamp half 3602,diaphragm 104, and upper clamp half 3600 are suspended on a set ofspring plungers 3100. The weight of upper clamp half 3600 is transferredthrough an elastomeric seal 3102, diaphragm 104, an elastomeric seal3104 and lower clamp half 3602. This arrangement maintains diaphragm 104in a non-tensioned state. Spring plungers 3100 include axiallydisposable end portions 3106 which are shown in their fully extendedpositions in FIG. 31. End portions 3106 and lower clamp half 3602 aresized to position diaphragm 104 at a plane above the adhesive and framesubassembly.

[0126] Pallet 2402 next travels to an edge treatment application station3200. Edge treatment application station 3200 includes a valve 3202coupled to a Cartesian arm 3204. Valve 3202 applies an edge treatcompound 3206 to the perimeter of diaphragm 104 as movement of pallet2402 is controlled within application station 3200. Motion control alongan X axis will be provided by track 2404 and motion along the Y and Zaxes will be provided by Cartesian arm 3204. Edge treat compound 3206functions to dampen unwanted harmonic or spurious vibrations ofdiaphragm 104 during speaker operation. Preferably, edge treat compound3206 is a liquid urethane oligomer acrylic monomer blend such as Dymax4-20539, that cures to a flexible solid.

[0127] Pallet 2402 travels next to a film tensioning and adhesive curingstation 3300. At station 3300, a radiation source 3302 extendsdownwardly and forces upper clamp half 3600 downward toward lower clamphalf 3602. The reaction force generated from springs within springplungers 3100 creates a clamping force between upper clamp half 3600 andlower clamp half 3602 to restrain the perimeter of diaphragm 104.Depending on the tensioning method utilized, the upper and lower clamphalves may be downwardly displaced to a predetermined position, or maybe displaced until a certain force is generated, or may be displaceduntil a certain resonance frequency is generated or until a certaindeflection of diaphragm 104 per unit load is defined.

[0128] As upper clamp half 3600 moves downward, diaphragm 104 is loweredinto contact with adhesive 406 positioned on planar mounting surface414. Upper clamp half 3600 continues to move downward stretching film400 over frame 102 until the desired tension in diaphragm 104 isachieved. When the tensioning process is complete, radiation source 3302is turned on to cure adhesive 406 and edge treat compound 3206. Aftercompletion of the exposure to the radiation, radiation source 3302 isturned off and retracted.

[0129] Any number of bonding agents may be used to couple diaphragm 104to frame 102. In the preferred embodiment, an adhesive curable byexposure to light in the visible spectrum such as Loctite Corp. 3106 isused. However, adhesives curable by exposure to ultra-violet light orother types of radiation may also be used. Certain pressure sensitivecompounds may also be used. Beneficially, pressure sensitive compoundsdo not require the use of light permeable diaphragms and fixturing thatallows light to pass to the bonded perimeter. Heat curable adhesives mayalso be used.

[0130] Pallet 2402 next travels to a terminal insertion station 3400.Terminal insertion station 3400 has a vibratory bowl feeder 3402 thatworks in conjunction with a terminal crimper 3404 and a terminalinsertion tool 3406. Vibratory bowl feeder 3402 orients a large quantityof terminal conductor assemblies 230 and individually feeds terminalassemblies one at a time to an escapement positioned below vibratorybowl feeder 3402. As pallet 2402 enters terminal insertion station 3400,a pressure pad 3408 extends downwardly from terminal crimper 3404 toengage speaker 100 near first end 204 and second end 206 of conductor106. Terminal insertion tool 3406 obtains a single conductor assembly230 from the escapement and installs it through apertures 214 and 216 offrame 102. During the insertion operation, the terminals piercediaphragm 104 at first end 204 and second end 206 to form an electricalconnection thereto. Crimper 3404 crimps the two electrical terminals todiaphragm 104. Additionally, crimper 3404 couples conductor assembly 230by mechanically deforming fastener 226 at the same time the electricalterminals are crimped. Terminal insertion tool 3406 and crimper 3404then retract.

[0131] Pallet 2402 next travels to a diaphragm trim station 3500.Diaphragm trim station 3500 includes a Cartesian arm 3502 equipped witha cutter 3504. Once pallet 2402 arrives at diaphragm trim station 3500,Cartesian arm 3502 lowers cutter 3504 into engagement with diaphragm 104to trim excess film 400 from diaphragm 104. The X axis motion for cutter3504 is provided by track 2404. Motion along the Y and Z axes isprovided by Cartesian arm 3502.

[0132] Pallet 2402 next travels to an unclamping station 2412. Atunclamping station 2412, upper clamp half 3600 is removed and placed onprotrusion 2500 of pallet 2402. The excess film that was previouslytrimmed from diaphragm 104 may be removed and discarded.

[0133] Pallet 2402 next travels to a test station 2414. At test station2414, speaker 100 is acoustically tested. During the acoustical test,the completed electro-dynamic loudspeaker 100 is excited using apredefined input. The actual acoustical output from each loudspeaker 100is compared to a target output. The actual output and target output arecompared to determine if the speaker meets quality standards previouslydefined. Tested loudspeaker 100 is removed from pallet 2402 and issorted according to the results of the acoustical test. Pallet 2402continues to travel along track 2404 and returns to frame loadingstation 2408 to begin the process once again.

[0134] With reference to FIG. 36, an alternate electro-dynamicloudspeaker 3600 is constructed from a first subassembly 3602 and asecond subassembly 3604. First subassembly 3602 includes diaphragm 104coupled to grille 220. Grille 220 is preferably an injection moldedcomponent constructed from a reinforced thermoplastic or thermosetcompound. Grille 220 may also be manufactured from aluminum, steel, orany other suitable material. Preferably, diaphragm 104 is coupled togrille 220 in a tensioned condition. The tension in diaphragm 104 may beproduced via a number of techniques including each of those previouslydescribed. However, diaphragm 104 may be tensioned after being coupledto grille 220.

[0135] Second subassembly 3604 includes frame 102, magnets 202 anddampener 228. Because two subassemblies are created, the total time tomanufacture loudspeaker 3600 maybe reduced. Balancing the constructionof two subassemblies allows for greater manufacturing flexibility andassembly line optimization. Furthermore, the use of grille and diaphragmsubassemblies may provide opportunities for constructing similarspeakers having different film-to-magnet clearances. By increasing thedistance between diaphragm 104 and magnets 202, speakers exhibiting anexpanded bandwidth with very low frequency limits may be exploited.

[0136]FIGS. 37 and 38 depict an alternate method for attaching adiaphragm 3700 to a frame 3702. Preferably, frame 3702 is constructedfrom a reinforced injection molded composite material. Frame 3702includes a body 3704 having a face 3706. A plurality of pins 3708protrude from face 3706. Pins 3708 are integrally molded with body 3704of frame 3702.

[0137] Diaphragm 3700 is substantially similar to diaphragm 104previously described. However, diaphragm 3700 includes a plurality ofapertures 3710 extending through its thickness. Apertures 3710 arepositioned to form a pattern corresponding to the location of theplurality of pins 3708 extending from face 3706.

[0138] Diaphragm 3700 is coupled to frame 3702 by inserting pins 3708through apertures 3710. Pins 3708 are sized to protrude a predetermineddistance above a top surface 3712 of diaphragm 3700. Diaphragm 3700 iscoupled to frame 3702 via a heat staking method where a distal portionof each of pins 3708 is melted and formed to define a head portion 3800extending beyond the edges of apertures 3710.

[0139]FIG. 39 depicts another alternate method of attaching a diaphragmto a frame or a grille. A frame 3900 includes a plurality of projections3902 extending from a mounting surface 3904. Diaphragm 104 is coupled toframe 3900 by contacting diaphragm 104 with each of projections 3902 andenergizing the assembly to cause local melting and fusion of thematerials. Local bonding at each of projections 3902 maybe accomplishedby applying heat and pressure with an external tool. Alternatively, thelocalized melting and bonding may be achieved by vibrating diaphragm 104and frame 3900 relative to one another. Furthermore, projections 3902may be excited using an ultrasonic energy source in conjunction with anaxial force engaging diaphragm 104 with each of the projections 3902.

[0140]FIG. 40 depicts an alternative method for attaching film 104 toframe 102. Frame 102 includes a coating 4000 applied to the exteriorsurfaces of frame 102. Preferably, coating 4000 is a thermoplasticmaterial applied by a power coating method. To attach film 104 to frame102, the perimeter of film 104 is engaged with an outer surface 4002 ofcoating 4000. Energy is added to the joint to create a localized meltingof coating 4000 and diaphragm 104. Energy may be supplied by vibratingfilm 104 relative to frame 102. Alternatively, frame 104 may be placedwithin a magnetic field to induction heat the frame and melt coating4000. The energy source is then turned off and film 104 is effectivelybonded to frame 104 via coating 4000.

[0141] While various embodiments of the invention have been described,it will be apparent to those of ordinary skill in the art that otherembodiments and implementations are possible that are within the scopeof this invention. Accordingly, the invention is not restricted exceptin light of the attached claims and their equivalents.

What is claimed is:
 1. A method of coupling a diaphragm to a structureof an electro-dynamic loudspeaker, comprising: providing a diaphragmhaving an electrical circuit coupled to a film, where the diaphragmincludes a center portion surrounded by a perimeter portion; providing aclamp, where the clamp is selectively moveable from an opened positionto a closed position; positioning the diaphragm within the clamp whenthe clamp is in the opened position; conforming the diaphragm to asubstantially flat plane to position the diaphragm in a non-tensionedstate; moving the clamp to the closed position and clamping theperimeter portion of the diaphragm thereby temporarily fixing thediaphragm in the non-tensioned state; displacing the center portion ofthe diaphragm to produce a predetermined tension in the film; applyingan adhesive curable by exposure to radiation to at least one of thediaphragm and a frame; and irradiating the adhesive to couple thediaphragm to the frame while the predetermined tension is maintained. 2.The method of claim 1 where the step of conforming the diaphragm to asubstantially flat plane includes drawing a vacuum through a platen andpositioning one side of the diaphragm adjacent the platen to cause thediaphragm to conform to the shape of the platen.
 3. The method of claim1 where the step of irradiating the adhesive includes exposing theadhesive to ultra-violet light.
 4. The method of claim 1 where the clampincludes an aperture revealing the center portion of the diaphragm andwhere the step of irradiating the adhesive includes exposing theadhesive to light within the visible spectrum.
 5. The method of claim 1where the step of irradiating the adhesive includes exposing theadhesive to infrared radiation.
 6. The method of claim 1 where the stepof displacing the center portion of the diaphragm includes engaging theframe with the diaphragm.
 7. A method of coupling a diaphragm to astructure for an electro-dynamic loudspeaker, comprising: providing adiaphragm having an electrical circuit coupled to a film, the diaphragmincluding a center portion surrounded by a perimeter portion;positioning the diaphragm on a base plate, the base plate including anaperture extending therethrough; axially moving a spider including aplurality of fingers extending from a hub toward the diaphragm;sandwiching the peripheral portion of the diaphragm between a portion ofeach of the fingers and the base plate; further axially moving thespider toward the diaphragm to impart a lateral force to the diaphragmand produce a tension in the center portion of the diaphragm; applyingan adhesive curable by exposure to radiation to at least one of thediaphragm and a frame; and irradiating the adhesive to couple thediaphragm to the frame while the predetermined tension is maintained. 8.The method of claim 7 where the step of irradiating the adhesiveincludes exposing the adhesive to ultra-violet light.
 9. The method ofclaim 7 where the step of irradiating the adhesive includes exposing theadhesive to light in the visible spectrum.
 10. A method of assembling anelectro-dynamic loudspeaker comprising: positioning a diaphragm havingan electrical conductor between a first plate and a second plate, whereeach of the first and second plates include an aperture extendingthrough its thickness and an annular groove circumscribing the aperture;positioning a first elastomeric member in the annular groove of thefirst plate; positioning a second elastomeric member in the annulargroove of the second plate; moving the first and second plates towardone another to tension the diaphragm between the first and secondelastomeric members; applying an adhesive curable by exposure toradiation to at least one of the diaphragm and a frame; and irradiatingthe adhesive to couple the diaphragm to the frame while the tension ismaintained.
 11. The method of claim 10 where the step of irradiating theadhesive includes exposing the adhesive to ultra-violet light.
 12. Themethod of claim 10 where the step of irradiating the adhesive includesexposing the adhesive to light within the visible spectrum.
 13. Themethod of claim 10 where the step of irradiating the adhesive includesexposing the adhesive to infrared radiation.
 14. A method of attaching adiaphragm for an electro-dynamic loudspeaker comprising: applying a loadto a frame to at least partially elastically deform the frame; applyingan adhesive curable by exposure to radiation to at least one of thediaphragm and a frame; irradiating the adhesive to couple the diaphragmto the frame while the load on the frame is maintained; and releasingthe load applied to the frame to tension the diaphragm.
 15. The methodof claim 14 where the frame is substantially rectangularly shaped. 16.The method of claim 15 where the frame is constructed from a materialhaving a modulus of elasticity less than 29,000 KSI.
 17. The method ofclaim 14 where the step of irradiating the adhesive includes exposingthe adhesive to ultra-violet light.
 18. The method of claim 14 where thestep of irradiating the adhesive includes exposing the adhesive to lightwithin the visible spectrum.
 19. The method of claim 14 where the stepof irradiating the adhesive includes exposing the adhesive to infraredradiation.
 20. A method of attaching a diaphragm to a frame for a planarloudspeaker, comprising; applying an adhesive curable by exposure toradiation to one of the frame and the diaphragm; compressing theadhesive between a portion of the diaphragm and a portion of the frame;and irradiating the adhesive with light within the visible spectrum tocause the adhesive to form a bond with the diaphragm and the frame. 21.The method of claim 20 where the step of irradiating includes exposingthe adhesive to infrared radiation.
 22. A method of attaching adiaphragm to a structure of an electro-dynamic loudspeaker comprising:tensioning a diaphragm having an electrical circuit coupled to a film;engaging the film with a plurality of projections extending from amounting plane extending about the periphery of a frame; inputtingenergy to the plurality of engagement locations to cause the projectionsto melt; and removing the energy source to solidify the projectionmaterial and couple the diaphragm to the frame.
 23. The method of claim22 where the step of inputting energy includes moving the diaphragm andframe relative to one another.
 24. The method of claim 22 where the stepof energizing includes applying a heat source to locally melt theprojections and a portion of the diaphragm.
 25. The method of claim 22where the step of energizing includes ultrasonically welding thediaphragm to the frame.
 26. A method of attaching a diaphragm to astructure of an electro-dynamic loudspeaker comprising: coating a framewith a thermoplastic material; engaging a diaphragm having an electriccircuit coupled to a film with an exterior surface of the coating;energizing the interface between the diaphragm and the coating to causelocalized melting of the coating; and removing the energy source toallow the coating to solidify and bond the diaphragm to the coating andthe frame.
 27. The method of claim 26 where the frame is constructedfrom a magnetizable material and where the step of energizing includesplacing the frame in a magnetic field to locally induction heat theframe and melt the coating.
 28. The method of claim 26 where the step ofenergizing the interface includes moving the film relative to the frame.29. A method of assembling an electro-dynamic loudspeaker, comprising:coupling a diaphragm to a grille to define a grille assembly, where thediaphragm includes an electrical conductor coupled to the diaphragm;elongating the diaphragm to obtain a desired tension; coupling aplurality of magnets to a frame to define a frame assembly; and couplingthe frame assembly to the grille assembly.
 30. The method of claim 29where the diaphragm is tensioned prior to being coupled to the grille.31. The method of claim 29 where the diaphragm is tensioned after beingcoupled to the grille.
 32. An electro-dynamic loudspeaker comprising: adiaphragm coupled to an electrical conductor, the diaphragm including aplurality of apertures extending therethrough; a frame having a bodydefining a mounting plane; the frame including a plurality of pinsextending from the mounting plane, the pins being selectively pliableupon the addition of energy, where the pins extend through the pluralityof diaphragm apertures and where a distal end of each pin is deformableto define a head portion for retaining the diaphragm to the frame. 33.The electro-dynamic loudspeaker of claim 32 where the frame and pins areintegrally formed from a thermoplastic material.
 34. The electro-dynamicloudspeaker of claim 33 where the pins are substantially cylindricallyshaped prior to deformation.
 35. A method of assembling anelectro-dynamic loudspeaker, comprising: positioning a diaphragm on aframe where the diaphragm has an electrical conductor and a plurality ofapertures extending through the diaphragm, where the frame includes aplurality of pins protruding therefrom; positioning the pins of theframe within the apertures of the diaphragm; engaging a surface of thediaphragm with a portion of the frame; and deforming a distal end ofeach pin to resist removal of the pins from the apertures to couple thediaphragm to the frame.
 36. The method of claim 35 further including thestep of heating the distal end of each pin.
 37. The method of claim 36where the plurality of pins are constructed from a thermoplasticmaterial.
 38. An electro-dynamic loudspeaker comprising: a diaphragmcoupled to an electrical conductor; and a frame having a plurality ofprojections extending from a surface, the projections being selectivelyenergizable to bond with the diaphragm and couple the diaphragm to theframe.
 39. The electro-dynamic loudspeaker of claim 38 where the frameand projections are integrally formed from a thermoplastic material. 40.The electro-dynamic loudspeaker of claim 39 where the plurality ofprojections are selectively energizable by an ultrasonic welder.
 41. Theelectro-dynamic loudspeaker of claim 39 where the plurality ofprojections are selectively energizable by relative movement between thediaphragm and the frame.
 42. A method of attaching a diaphragm to aframe for a planar loudspeaker, comprising; tensioning the diaphragm;applying a pressure sensitive adhesive to one of the frame and thediaphragm; compressing the adhesive between a portion of the diaphragmand a portion of the frame to couple the frame to the diaphragm.
 43. Themethod of attaching a diaphragm of claim 42 where the frame includes abody portion and a substantially planar mounting surface encompassingthe body portion, where the diaphragm includes a center portion surroundby a perimeter portion, and where the perimeter portion of the diaphragmand the mounting surface of the frame compress the adhesive.
 44. Themethod of attaching a diaphragm of claim 42 where the adhesive is atwo-part adhesive.
 45. The method of attaching a diaphragm of claim 42further including coupling a plurality of magnets to the body portion ofthe frame prior to coupling the diaphragm to the frame.